External wall insulation · Northern Ireland
External wall insulation in County Londonderry
Planning external wall insulation anywhere in County Londonderry? We cover towns including Derry~Londonderry and Coleraine, and check planning and building control for each address. For homes in County Londonderry, the survey starts with the wall itself: solid brick, stone or concrete, and whether any old render is sound enough to insulate over.
- Free survey and fixed written price
- Guide price from £105 per m² + scaffold, 0% VAT
- Planning and building control checked for Northern Ireland
Free survey in County Londonderry
Tell us the postcode and what you need.
What's included
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- Work happens outside, so you can live at home throughout
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
What we look for in County Londonderry
Northern Ireland has many rendered and pebble-dashed homes, older solid-walled rural houses, and estates built by the Housing Executive.
Parts of County Londonderry fall in the higher wind-driven rain exposure bands, especially coastal and upland sites, so render specification, movement joints and detailing at cills, verges and the base of the wall matter more than usual.
We plan EWI in County Londonderry around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Nation
- Northern Ireland
- Region
- Northern Ireland
- Towns covered
- Derry~Londonderry, Coleraine, Limavady, Magherafelt
- Guide price
- From £105 per m² + scaffold · 0% VAT
Permissions in Northern Ireland
In Northern Ireland, permitted development is set by the Planning (General Permitted Development) Order (NI) 2015. Changing the external appearance of a house may need permission, and conservation areas, flats, commercial buildings and listed buildings need planning permission or listed building consent. Check with your council's planning office.
Insulating external walls is building work under the Building Regulations (Northern Ireland) 2012, handled by council building control, with Technical Booklet F1 covering conservation of fuel and power in dwellings.
How does external wall insulation work?
Heat moves out through a wall faster when the wall is solid or poorly insulated. EWI wraps the outside face in a continuous layer of insulation, so the masonry stays on the warm side and the cold bridges at floor and party-wall junctions are reduced. The boards are bonded with adhesive and, on most walls, mechanically fixed. A base coat with an embedded glass-fibre mesh goes over the top, then a primer and the decorative finish.
Because the wall itself sits inside the insulation, it stays warmer and drier, and the rooms keep their full size. That is the main difference from internal insulation.
External wall insulation prices in County Londonderry
| Item | Guide price | Notes |
|---|---|---|
| EPS system with silicone render | £105–£145 per m²0% VAT | Most common choice for houses |
| Mineral wool system | £125–£170 per m²0% VAT | Non-combustible, vapour-open |
| Brick-slip finish over insulation | £185–£260 per m²0% VAT | Where a brick look is wanted |
| Three-bed semi, EPS + silicone (incl. scaffold) | £10,200–£17,7000% VAT | 80–100 m² of wall; depends on detailing and access |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
How it works
Tell us about the property
Use the quote tool or form, or call. Photos help.
Free survey
We measure, check the walls and confirm approvals.
Fixed written quote
System, details, access, exclusions and VAT in writing.
Installation
Scheduled for suitable weather, with a clear programme.
External wall insulation in County Londonderry: questions
Does external wall insulation cause damp?
Not when it is specified and detailed properly. Problems usually come from poor detailing: no starter track above the damp-proof course, gaps at cills and penetrations, or a vapour-closed system on a wall that needs to breathe. The survey checks moisture, ground levels and the wall type before a system is chosen.
How much does external wall insulation cost?
Our guide price for EWI is £105–£170 per m² of wall depending on the system, plus scaffolding. A typical three-bed semi with EPS and silicone render comes to roughly £10,200–£17,700 for the whole house, including scaffold. Installing insulation in a home is zero-rated for VAT until 31 March 2027, so that's the total. You get a fixed written price after a free survey.
How long does external wall insulation last?
A well-installed render system is commonly expected to last 25–30 years or more, with occasional cleaning and inspection of sealants. The system manufacturer's documentation states the expected service life for the specific build-up.
Do you cover all of County Londonderry?
Yes. We survey and quote external wall insulation across County Londonderry, including Derry~Londonderry, Coleraine, Limavady, Magherafelt.
Do I need planning permission in Northern Ireland?
In Northern Ireland, permitted development is set by the Planning (General Permitted Development) Order (NI) 2015. We check your address before quoting.